Yes, I would say that you have been the victim of a scam and you have a potentially damaged piece of goods there.  Time to toss it and buy a new one from a reputable dealer.  The largest flash drive out there right now is about 64Gb (there might be a 128Gb) and they cost about US $300 right now.  So, if someone is selling you something for way under that range and all, it is likely a scam.